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Evidence for a subsurface ocean on Europa
M H Carr1, M J Belton, C R Chapman
1US Geological Survey, Menlo Park, California 94025, USA. carr@astmnl.wr.usgs.gov
Nature
|February 5, 1998
Summary
High-resolution Galileo images of Jupiter's moon Europa reveal evidence of mobile icebergs, supporting the presence of a shallow subsurface ocean. This finding offers new insights into Europa's geological activity and potential habitability.
Area of Science:
- Planetary Science
- Astrobiology
- Geology
Background:
- Spectroscopy and gravity data suggest Europa has a 150 km icy crust and rocky interior.
- Voyager images show linear features (lineae) and young terrain, hinting at a subsurface liquid water layer.
- Previous low-resolution images (<2 km/pixel) hindered confirmation of a subsurface ocean.
Purpose of the Study:
- To present high-resolution Galileo spacecraft images of Europa.
- To investigate evidence for mobile icebergs and shallow subsurface water.
- To assess the widespread nature of these phenomena.
Main Methods:
- Analysis of high-resolution (54 m/pixel) Galileo spacecraft images of Europa.
- Examination of lower-resolution images covering larger regions.
Main Results:
- Discovery of mobile 'icebergs' on Europa's surface.
- Detailed terrain morphology strongly supports shallow liquid water, past or present.
- Observations suggest these phenomena are widespread across Europa.
Conclusions:
- High-resolution imagery provides compelling evidence for shallow subsurface water on Europa.
- The findings support models involving tidal heating and geological activity driven by a subsurface ocean.
- Europa's dynamic icy shell and potential for liquid water enhance its astrobiological significance.
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